Question

Halp me this question test

Answer 1

+) Replace x = (2/5)y - 4 into 3x - 9y = -51

`3 * ( (2)/(5) y - 4) - 9y = - 51 \\`

`(6)/(5) y - 12 - 9y = - 51`

`(6)/(5) y - 9y = - 51 + 12 = - 39`

`( - 39)/(5) y = - 39`

`y = (- 39) / (( - 39))/(5) = ( - 39) * (5)/(( - 39))`

`y = 5`

`x = (2)/(5) y - 4 = (2)/(5) * 5 - 4 = 2 - 4`

`x = - 2`

Ans: (x;y) = (-2;5)

Ok done. Thank to me >:33

Answer 2

answer is (-2,5)

Explanation:

gonna make 2 by 5 into Percent

x=0.4y-4

3x-9y=-51

step 2 Add 3 into first column and make it negative

-3x=-1.2y+12

then move y to other side

-3x+1.2y=12

3x-9y=-51

-7.8y=-39

y=5

U got y now

add it into y in first column

x= 2/5(5)-4

then it be 2-4= -2

x=-2